Bip39 passphrase https://files.fm/u/2eemhhak2q#design Though it utilizes BIP32 system you could still import BIP39 seeds into Electrum wallet. Also in addition to BIp32 There is certainly BIP44 Edition which some wallet use for your technology of seeds. Some wallets can import different seed phrases and some have only a person standard. https://bookmarkilo.com/story20100543/bip39-hash-helping-the-others-realize-the-advantages-of-bip39-passphrase-https-cutt-ly-uryc5rw7